Question

I'm try to complete an Operating Systems assignment where we have 8 processes, and each process has between 14-18 bursts.

We have to do a FCFS simulation, SJF simulation, and MLFQ simulation.

I am well aware of how to calculate everything for the processes when we just have one set of bursts to deal with, however these processes have way more than that. I am a very visual learner, I would love if someone could explain to me how to calculate these and help me come up with a C++ algorithm to sort through my arrays that I've set as p1-p8 and put all of the bursts inside the array slots.

These are my processes and the the processes go: {CPU burst, I/O time, CPU burst, I/O time, CPU burst, I/O time,........, last CPU burst}

P1 {5, 27, 3, 31, 5, 43, 4, 18, 6, 22, 4, 26, 3, 24, 4}

P2 {4, 48, 5, 44, 7, 42, 12, 37, 9, 76, 4, 41, 9, 31, 7, 43, 8}

P3 {8, 33, 12, 41, 18, 65, 14, 21, 4, 61, 15, 18, 14, 26, 5, 31, 6}

P4 {3, 35, 4, 41, 5, 45, 3, 51, 4, 61, 5, 54, 6, 82, 5, 77, 3}

P5 {16, 24, 17, 21, 5, 36, 16, 26, 7, 31, 13, 28, 11, 21, 6, 13, 3, 11, 4}

P6 {11, 22, 4, 8, 5, 10, 6, 12, 7, 14, 9, 18, 12, 24, 15, 30, 8}

P7 {14, 46, 17, 41, 11, 42, 15, 21, 4, 32, 7, 19, 16, 33, 10}

P8 {4, 14, 5, 33, 6, 51, 14, 73, 16, 87, 6}

Answer 1

Given n processes with their burst times, the task is to find average waiting time and average turn around time using FCFS scheduling algorithm.
First in, first out (FIFO), also known as first come, first served (FCFS), is the simplest scheduling algorithm. FIFO simply queues processes in the order that they arrive in the ready queue.
In this, the process that comes first will be executed first and next process starts only after the previous gets fully executed.
Here we are considering that arrival time for all processes is 0.

How to compute below times in Round Robin using a program?

1. Completion Time: Time at which process completes its execution.
2. Turn Around Time: Time Difference between completion time and arrival time. Turn Around Time = Completion Time – Arrival Time
3. Waiting Time(W.T): Time Difference between turn around time and burst time.
   Waiting Time = Turn Around Time – Burst Time